Expert Sudoku to Print
Expert sudoku puzzles have about 24 to 28 given numbers and cannot be finished with singles, pairs, triples or X-Wings. Each one needs a swordfish or an XY-Wing, or longer chains of reasoning. They still have exactly one solution, so logic is always enough, and the answers are on the last page.
Expert Sudoku generator
The generator needs JavaScript. The puzzle shown below is a fixed sample you can print with your browser.
#X-00001 · 28 given numbers
How to print it
- Choose a level and how many puzzles you want on each page.
- Choose the number of pages and A4 or US Letter paper.
- Press Print, or Download PDF to save the puzzles as a file.
- Keep the last page: it holds the answers, marked with each puzzle’s code.
What expert means here
The grader knows singles, pairs, pointing pairs, box/line reduction, triples, X-Wing, swordfish and XY-Wing. A puzzle is called expert if it needs a swordfish or XY-Wing, or if it gets stuck even with all of them. In that last case you need longer chains, such as forcing chains or coloring, which the grader does not try.
In our test of 1000 expert puzzles, most were of the second kind. That means many expert puzzles here are truly tough. They are made for people who enjoy long solving sessions.
Techniques for expert puzzles
- Swordfish: an X-Wing with three rows and three columns. One digit has two or three possible cells in each of three rows, all inside the same three columns. It can be removed from the rest of those columns.
- XY-Wing: a cell with two candidates, X and Y, that sees one cell with X and Z and another with Y and Z. Whichever way the first cell goes, one of the other two is Z, so Z can be removed from any cell that sees both.
- Chains: follow a line of "if this cell is 4, that one must be 7" steps. If both choices lead to the same result, that result is true.
Before you print
Expert puzzles take longer to generate, because many grids are tried before one needs the right techniques. A booklet of many pages can take a minute or more. The page shows its progress while it works.
All levels
| Level | Given numbers | Median | Techniques needed |
|---|---|---|---|
| Easy | 36–40 | 38 | Naked and hidden singles only |
| Medium | 30–35 | 31 | Singles plus naked or hidden pairs, pointing pairs and box/line reduction |
| Hard | 26–31 | 28 | All of the above plus naked or hidden triples or an X-Wing |
| Expert | 24–28 | 28 | Swordfish or XY-Wing, or longer chains that go beyond the techniques the grader knows |
Given numbers measured on 1000 generated puzzles per level (October 15, 2026). The level comes from which techniques a step-by-step solver needs, not from the count of given numbers.
Frequently asked questions
What is the hardest level of sudoku?
There is no standard scale, and every book or site names levels its own way. Here, expert is the top level: puzzles that need swordfish, XY-Wing or longer chains. Some puzzle makers rate puzzles with numeric scores instead.
Do expert sudoku need guessing?
No. Every expert puzzle has exactly one solution, so it can be solved by logic. Some need long chains of reasoning that feel like trial and error. Writing all candidates carefully is the best way to see them.
What is a swordfish in sudoku?
A swordfish is a bigger X-Wing. One digit is limited to the same three columns in three different rows. The digit must take one cell in each of those columns within those rows, so it can be removed from the rest of the three columns.
Why does printing expert sudoku take longer?
The generator tries many grids and checks each step with both a solution counter and a technique grader. Expert puzzles are rarer than easy ones, so more grids are tested. Your computer does all of this locally.
How do I check my expert sudoku?
Use the answer page. Each answer grid has the puzzle code, so you can find the right one. You can also open the code in Play on screen and turn on Show mistakes.
Last updated: October 15, 2026